Antibacterial and anti-biofilm properties of Cymbopogon martini (Roxb.) essential oil and geraniol against Staphylococcus aureus strains

Cymbopogon martini (Roxb.) Wats, known as palmarosa, a perennial aromatic grass cultivated for its essential oil, represents a promising industrial crop widely used in perfumery, cosmetics, self-care products, and aromatherapy, with emerging applications in pharmaceutical formulations. This study investigates the chemical composition and antimicrobial potential of Cymbopogon martini essential oil and one of its main components, geraniol, against Staphylococcus aureus from clinical isolates and commercial sources. The effect upon planktonic state was assessed obtaining the MIC and MBC values. Biofilm viability and biomass were quantified using resazurin and crystal violet assays, respectively. Additionally, membrane disruption was explored as a potential mechanism of action. Potential toxicity was evaluated in A549 and HaCaT cell lines and in adult Artemia spp. GC-MS analysis revealed the presence of geraniol as the major compound (75.29 %) but also other terpenes like geranyl acetate (10.39 %), ( E )-β-caryophyllene (3.14 %), linalool (2.90 %) and trans-β-ocimene (1.36 %). The essential oil displayed lower MIC and MBC values (MIC: 300–350 µg ml −1 ; MBC: 400 µg ml −1 -450 µg ml −1 ) than the pure geraniol (MIC: 500 µg ml −1 ; MBC: 550–600 µg ml −1 ). Results showed nearly 100 % inhibition of biofilm formation across tested concentrations (500 µg ml −1 to 1000 µg ml −1 ). Unlike vancomycin, the essential oil remained active in disrupting established S. aureus biofilms (IC₅₀ = 554.47 µg ml −1 ). No cytotoxicity was observed in human cells at the range of concentrations from 250 µg ml −1 to 1000 µg ml −1 . These findings highlight Cymbopogon martini as a valuable industrial crop with potential as a plant-derived antibiofilm agent. • Cymbopogon martini, palmarosa , is mainly cultivated for its essential oil used in perfumes, cosmetics and aromatherapy • Palmarosa essential oil is characterized by the presence of geraniol (75 %) • Palmarosa essential oil and geraniol exert antibacterial properties against different Staphylococcus aureus strains • Palmarosa essential oil acts both on biofilm formation and biofilm disruption